In a world of humans with perfect knowledge, ethical responsibility would not be a difficult question. You're flying the flag of the empire. You're supporting its wars. Its wars are killing children. For profit. You're evil. You cause harm, you're guilty. The end.
This is the Arthur Silber worldview. Clean, simple, convenient. I agree with it, mostly.
But humans do not have perfect knowledge, and even when they have access to it, there are processes, defenses mainly, that will prevent them from understanding it.
We might say there are two types of responsibility, causal and ethical. The first refers to the effects of one's actions. The second refers to what we can blame someone for, how we justify our emotions toward people who hurt us or others we empathize with. If I'm trying to save the Iraqis from Saddam Hussein but it turns out I'm actually making things worse fighting for the empire, I'm causally responsible for the damage done. But am I ethically responsible? What could I have known and how could I have known it?
Now my parents raised me Catholic. At age seven, I was in a tiny room with a strange man saying, "forgive me father for I have sinned, it's been three weeks since my last confession." I was apologizing for my existence, essentially, accepting that I was a horrible piece of shit. I remember telling my mom at one point that the devil was trying to get me to say bad words but I was so good I wouldn't even give him the pleasure of thinking bad words. I was mind-fucked is what I'm saying. My parents were prominently involved. They put me in that position. They decided I would exist, first of all, and then they watched as I was abused. Now, causally, there's no doubt in my mind that they damaged the shit out of me. I was suicidal by age 14 or so. This is not something that happens on its own. Fear of abandonment by God is something my parents and their stand-ins put in me.
Are they ethically responsible, and to what extent, and how, and why? Given their particular position in the world, how could they have known? Was there edifying information available to them that they rejected, evilly? What edifying information did they reject, why, and what processes would have led them to making decisions that would not have harmed me?
(For an Alice Miller-inspired thinker like Silber, it would be easy to say I'm protecting my parents here. But I've told my parents that their religion almost killed me, that their Church is evil, that their empire is evil, etc. Intellectually, I know they're at fault and grant them no pedastals.)
I have a metaphor for this, unoriginal though it may be. I'm in a tunnel with a flashlight. At the outer edges of the light, there are things I can see only dimly. Beyond that, nothing, just darkness. Is it a simple act of will that lets me see what I do? Is my own acceptance of my complicity in these violent systems a result of my will and therefore admirable?
I've suggested before that freedom/determinism is a false dichotomy, that the choices are: either everything is free or everything is determined. I declared that I'm as free as a rock, and this is good (arbitrarily). There is a difference between rocks and me of course but I'd like to suggest that this difference is best divorced from the freedom/determinism question. My brain has me interacting with the world in a way rocks can't, but is this difference describable in terms of freedom? I don't think so. Abstractions do not give you freedom. Math does not give you freedom. Awareness that more than one option exists does not give you freedom.
This brings me to a related point. In a recent post, just after a quote by an imperialist explaining how the U.S. conquest of the Phillipines was all for the better of the people of that country, Silber states: "[The rulers] know exactly what they're doing." No, they don't. There's an important difference between "I want to kill heathens/barbarians/Satan spawn/threats to humanity/Others/people who want to hurt my family/vermin" and "I want to kill humans who are just like me in every way that ethically matters." I'd personally get behind the killing of people who want to carry out Satan's plans of causing human suffering because I oppose unneccessary human suffering. I just don't think such people exist. The Other is a myth. The rulers do not know what they're doing in the way that Silber does. If they did, they wouldn't do it. Good will is fake.
I think, for all intents and purposes, it's probably a good idea to focus only on the actual harm being caused to humans by humans. It's best not to make it personal, not to worry about the question of ethical responsibility. "They're evil, fuck them!" is stupid. Worse still, it's tribalism. I don't mean one shouldn't be angry. I mean that anger, while serving a good purpose, should be understood in terms of real harm, not personal demons or evildoers.
In sum, ethical responsibility IS causal responsibility, but the minds of those who cause harm are irrelevant except insofar as knowledge of them helps one prevent future harm.